Connector assembly clip

ABSTRACT

An optical connector assembly comprising (a) a plurality of identical connectors, each connector being connected to a jacketed optical cable, each connector comprising a generally rectangular housing having a top, a bottom and two sides, and having a plug end for insertion into a mating receptacle and a cable end for receiving an optical cable, the housing having a recess along each of the two sides; and (b) a clip holding the plurality of connectors together in a side-by-side relationship, the clip having a bottom portion, first and second end walls extending perpendicularly from the bottom portion, and one or more intermediate portions extending perpendicularly from the bottom portion between the first and second end walls, each of the one or more intermediate portions having a first face facing the first end wall and a second face facing the second end wall, wherein the first end wall and a first face of one of the one or more intermediate portions are received in the recess of one of the connectors and the second end wall and a second face of one of the one or more intermediate walls are received in the recess of another of the connectors such that the connectors are held in a side-by-side arrangement.

REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No.60/452,868 which was filed on Mar. 6, 2003 and is hereby incorporated byreference.

FIELD OF INVENTION

The present invention relates generally to optical fiber connectors,and, more specifically, to duplex connector assemblies.

BACKGROUND OF INVENTION

Optical fiber connectors are an essential part of substantially alloptical fiber communication systems. For instance, such connectors areused to join segments of fiber into longer lengths, to connect fiber toactive devices such as radiation sources, detectors and repeaters, andto connect fiber to passive devices such as switches and attenuators.The principal function of optical fiber connectors is to hold an opticalfiber such that its core is axially aligned with the optical path of thedevice to which the connector is mating (herein “mating device”). Thisway, the light from one fiber is optically coupled to the optical pathof the mating device.

A typical connector comprises a housing containing a ferrule which holdsone or more fibers. The ferrule is biased forward in the housing suchthat, when the connector is mated to the mating device, the fiber in theferrule urges against the optical path of the mating device. There aremany different prior art connectors currently available for establishingsuch optical connections, including, for example, SC, ST and FCconnectors and more-recent “small form factor” designs such as MTRJ, MU,LC, MPX and MPO-type connectors.

In networks and communication equipment that utilize optical fibers,often optical fibers are mated in pairs corresponding to a transmittingoptical fiber and a receiving optical fiber. It is essential that theconnections be made correctly. For example, it is important to ensurethat a transmitting optical fiber is connected to another transmittingfiber or to a transmitter port of a transceiver and that a receivingoptical fiber is connected to another receiving optical fiber or to areceiver port of a transceiver.

To ensure proper polarity, duplex optical connectors have been used inthe communications industry to couple two simplex optical fiberstogether in a duplex arrangement to allow both optical fibers to beconnected simultaneously to ports located on communication equipment orto an adapter which connects pairs of optical fibers together. Forexample, U.S. Pat. No. 5,579,425 (hereinafter the '425 patent) disclosesan optical fiber duplex connector based on the LC connector, which isshown in FIG. 3. The duplex connector is formed by joining together apair of simplex LC connectors 51 with a plastic clip 52. Each clip 52includes a first planar structure 53 having a pair of cylindrical pins54 of different diameters thereon. The cylindrical pins 54 are press fitinto associated openings 55 formed in the simplex connectors 1, therebyconnecting them together. The plastic clip 52 has information thereon,such as the letters A and B, which identifies the correct polarizationof the duplex connector with respect to its mating device (e.g., anadapter). Although the plastic clip design of the '425 patent provides anovel way for forming a duplex connector, it has been found that thecylindrical pins tend to have marginal holding strength and aregenerally not as robust as desired. Furthermore, since the clip isintended to augment the connector's latch mechanism—i.e., it providesthe user with a larger area to actuate the latch—the connector issomewhat dependent on the clip. This dependence undermines the use ofthe connectors in simplex applications. In other words, by designing aconnector to work in conjunction with the clip, the connector does notfunction as well independently, perhaps necessitating differentconnectors for simplex applications.

FIG. 4 illustrates another known optical fiber duplex connector. Theduplex connector shown in FIG. 3 comprises two connectors 60 clippedtogether by a duplex yoke 61, which attaches near the back ends of theconnector housings. Once the duplex yoke 61 has been attached, endportions of two strain relief boots 62 are pushed over crimp cans 63extending from the back ends of the connector housings. Heat fit tubing64 is attached to the fiber cable 65 and to the ends of the crimp cans63. Each of the connectors 60 comprises a two-piece housing. The frontportion 16 of the housing has a latch 67 thereon and houses the ferruleassembly (not shown) that holds the end of the optical fiber. The backportion 68 of the housing contains a metal insert (not shown) thatassists the connector in handling side loading. The optical fiber cable65 contains aramid fiber strength members that are crimped to the metalinsert. As with the duplex connector of the '425 patent, the duplex yoke61 attaches to the connector housings. The housings of the connectors 60must be sufficiently long to enable the yoke 11 to be attached to thembecause the connectors 60 require the back portions 68 of the housings.As with the duplex connector of the '425 patent, the duplex connectorshown in FIG. 4 is used normally on the front side ofreceptacles/adapters, rather than on the back side. Although thisconnector assembly is suitable for its intended purpose, the fact thatthe anti-snag guard/latch actuation pad is integral with the duplex clipmilitates in favor of using the connector with a duplex clip—even to agreater extent than with the connector of the '425 patent. Thepreference to use different connectors for simplex and duplexapplications tends to increase the number of components of the connectorsystem, thereby increasing inventory costs and, in general, addingcomplexity to the system.

In U.S. Pat. No. 6,409,392, a duplex clip is disclosed for coupling twosimplex connectors of the type used in behind-the-wall (BTW)applications to form a duplex connector. Connectors suitable for BTWapplications are typically considerably shorter in length than thetwo-piece connectors 50 and 60 shown in FIGS. 3 and 4, respectively. Asdisclosed in the '392 patent, the duplex clip comprises a clip body thatis adapted to receive and grip outer surfaces of the boots of the pairof simplex connectors to hold the simplex connectors in close spatialproximity to one another, thereby forming a duplex connector. Twogenerally cylindrical bores are formed in the clip body and the innersurfaces of each of the bores are adapted to grip the outer surfaces ofthe boots. Slots are formed in the clip body to provide the bores withgenerally C-shaped cross-sections. Cables can be passed through theslots to enable the clip to be clipped onto a pair of simplex connectorswhen the simplex connectors are coupled to or decoupled from areceptacle or adapter.

Although the duplex clip configuration of the '392 patent provides for aconnector which can be used in BTW applications, the applicants haveidentified a number of shortcomings with this configuration. First, theduplex clip of the '392 patent's requires the use of a boot on the endof the connector. Although boots are common, they are not necessary forall applications. The duplex clip of the '392 patent would be unsuitablefor applications in which the boot was not used. Furthermore, the yokeconfiguration of the duplex clip disclosed in the '392 patent isrelatively bulky and extends well beyond the periphery of the housing ofthe connector. This can be problematic in certain applications wherethere is a need to minimize the space occupied by the connector.

Therefore, there is a need for a connector system which provides for aduplex connector assembly in which the connectors used for simplex andduplex connectors are identical, and in which the clip used to form theassembly is simple and unobtrusive while nevertheless providing for arobust interconnection system that does not require the use ofadditional components (e.g., a boot). The present invention fulfillsthis need among others.

SUMMARY OF THE INVENTION

The present invention provides for a connector system which facilitatesthe assembly of two or more identical connectors using a simple androbust clip. Specifically, the system employs a simple, but effective,clip which engages a contoured section of the housings of standardsimplex connectors to hold two or more of them securely in place.

The connector system of the present invention offers a number ofsignificant advantages over prior art connector systems. First, it usesidentical simplex connectors as building blocks for larger, more-complexconnector assemblies (e.g., duplex and quad connector assemblies). Thus,there is no need to stock and maintain an inventory of connectorsintended specifically for either simplex or duplex connector assemblies.Second, since the clip engages each connector around its periphery, theclip and connecter are mechanically interengaged, thereby improving thestructural integrity and reliability of the connector assembly. Forexample, by way of contrast, the assembly does not rely on a frictionfit between pegs and holes of the connectors and clip. Such a robustconnector assembly system is very desirable in applications whereexternal aggression on the connector is common. Third, the clip of thepresent invention is very discrete, having a profile that does notextend much beyond the periphery of the housing, if at all. In apreferred embodiment, the clip is received in a recess of the connector,further minimizing its profile in the connector assembly. Fourth, theclip of the present invention cooperates with simplex connectors withoutthe need for additional components such as boots or other cable dress.This further increases its simplicity and ease-of-use. Finally, the clipcan be installed before or after the connectors are terminated—it istotally independent of the fiber cable connected to the connector. Thisallows duplex and other assemblies to be formed in the field.

One aspect of the invention is an optical connector assembly comprisingthe clip. In a preferred embodiment, the connector assembly comprises(a) a plurality of identical connectors, each connector being connectedto a jacketed optical cable, each connector comprising a generallyrectangular housing having a top, a bottom and two sides, and having aplug end for insertion into a mating receptacle and a cable end forreceiving an optical cable, the housing having a recess along each ofthe two sides; and (b) a clip holding the plurality of connectorstogether in a side-by-side relationship, the clip having a bottomportion, first and second end walls extending perpendicularly from thebottom portion, and one or more intermediate portions extendingperpendicularly from the bottom portion between the first and second endwalls, each of the one or more intermediate portions having a first facefacing the first end wall and a second face facing the second end wall,wherein the first end wall and a first face of one of the one or moreintermediate walls are received in the recess of one of the connectorsand the second end wall and a second face of one of the one or moreintermediate walls are received in the recess of another of theconnectors such that the connectors are held in a side-by-sidearrangement.

Another aspect of the invention is the clip for facilitating theconnector assembly described above.

Other aspects, advantages, and novel features of the invention willbecome more apparent from the following detailed description when takenin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

The invention and its mode of operation will be more clearly understoodfrom the following detailed description when read with the appendeddrawings in which:

FIG. 1 is an exploded view of a preferred embodiment of the presentinvention using a polymeric clip;

FIGS. 2 a and 2 b are perspective views of a preferred embodiment of thepresent invention using a metallic clip in a preassembled and assembledstate, respectively;

FIG. 3 is a perspective view of a prior art duplex connector beingclipped together via a duplex clip to form a duplex connector; and

FIG. 4 is a perspective view of a prior art duplex connector beingclipped together via a duplex yoke to form a duplex connector.

DETAILED DESCRIPTION OF INVENTION

Referring to FIG. 1, a preferred embodiment of the connector system ofthe present invention is shown. The connector assembly 1 comprises aplurality of identical simplex connectors 10. Each connector comprises agenerally rectangular housing 28 having a top 29, a bottom 30, sides 31a, 31 b and two ends-a front or plug end 32 and a back or cable end 33.The plug end 32 is suitable for insertion into a mating receptacle (notshown) while the cable end 33 is adapted for receiving and securing anoptical cable (not shown). The housing 28 has a recess 25 along each ofthe two sides 31 a, 31 b. The connector assembly also comprises a clip11 for holding the plurality of connectors 10 together in a side-by-siderelationship. The clip has a bottom portion 19, first and second endwalls 20 a, 20 b extending substantially perpendicularly from the bottomportion 19, and one or more intermediate portions 21 also extendingsubstantially perpendicularly from the bottom portion 19 between thefirst and second end walls 20 a, 20 b. Each of the one or moreintermediate portions 21 has a first face 34 a facing the first end wall20 a and a second face 34 b facing the second end wall 20 b. The clip 11and connectors 10 cooperate such that, when the clip 11 is engaged withthe connectors 10, the first end wall 20 a and a first face 34 a of oneof the one or more intermediate portions 21 are received in the recess25 of one of the connectors 10 and the second end wall 20 b and a secondface 34 b of one of the one or more intermediate walls 21 are receivedin the recess 25 of another of the connectors 10 such that theconnectors 10 are held in a side-by-side arrangement. The connectors andthe clip of the connector assembly of the present invention arediscussed in greater detail below.

The connector depicted in FIG. 1 conforms to the LC-type connectorstandard, accordingly the details of this connector which are commonwith those of a standard LC-type connector will not be discussed indetail herein. It should be understood, however, that the presentinvention is not restricted to an LC-type connector or any otherconnector type for that matter, and can be used with a variety ofconnector systems, including, for example, the MU, ST, FC, SC, MPX, andMPO connector systems. Although the present invention may be practicedwith any connector system, it is particularly well suited for small formfactor single fiber connectors such as the LC and MU-type connectors.

The connector 10 comprises a generally-rectangular housing 28 having afront body 12 and a rear body 13. As with a typical LC connector, theembodiment of the connector in FIG. 1 comprises a latch 15, an anti-snagguard 16 covering the end of the latch 15, and a crimped lug 14 forsecuring the connector to an optical cable on rear body 13. Likestandard simplex LC connectors, connector 10 also has an individualactuation pad l0 a (see FIG. 2). The connector of the present inventiondeparts from a standard LC connector, however, in that it has a recess25 near its cable end for receiving the clip 11. Preferably, the recess25 is located behind the portion of the connector which is received inthe receptacle and forward of the crimp lug 14. In this particularembodiment, the recess is located below the anti-snag guard 16. Withthis configuration, the anti-snag guard 16 and the recess features 25can be integrated on a common rear body 13. The recess can be anyconfiguration suitable for receiving a clip which contacts both sides ofthe connector to hold it securely. In the embodiment shown in FIG. 1,the recess is a continuous recess which extends from one side of theconnector 31 a down around the bottom 30 of the connector and up theother side 31 b. It may be preferable to add certain polarizationmaintaining features to the recess to ensure that it can receive theclip only in a certain orientation. For example, referring to FIG. 2 a,the polarization-maintaining features of the recess may be anasymmetrical geometry, specifically, a recess 25 with a deeper portion27, which is designed to received a rib 26 a on the clip (discussed indetail below) only when the clip 11 a is in a certain orientationrelative to the connector 1 a.

It is worthwhile to mention that the connectors 10 are not specificallydesigned for a duplex assembly. That is, the connectors 10 are designedas stand-alone simplex connectors which can be used as building blocksto form assemblies of any number of connectors, such as a duplex or quadassemblies, using the clip of the present invention.

Referring to FIG. 1, the clip 11 of the present invention is shown. Asmentioned above, the clip has a bottom portion 19, first and second endwalls 20 a, 20 b extending perpendicularly from the bottom portion 19,and an intermediate portion 21 extending perpendicularly from the bottomportion 19 between the first and second end walls 20 a, 20 b. Althoughthe clip is described as having a “bottom” section, it should beunderstood that this is a relative term used for illustrative purposesand should not be construed to limit the scope of the intention. Inother words, it is well within the scope of this invention for the clipto be inverted such that the bottom faces upward. The intermediateportion 19 has a first face 34 a facing the first end wall 20 a and asecond face 34 b facing the second end wall 20 b. The number ofintermediate portions determines the number of connectors the clip canaccommodate (i.e., no. of connectors=no. of intermediates portions +1).For example, in the embodiment shown in FIG. 1, the clip has a singleintermediate portion, and, thus, it can accommodate two connectors.

In the case of a duplex assembly, each connector will be held by oneface of the intermediate position and one end wall of the clip. If morethan two connectors are held together in a side-by-side arrangement,then the interior-held connectors are held in place by the intermediateportions of the clip and do not contact the end walls. It should also beappreciated that the clip may contain a second set of end walls andintermediate portions which extend from the other side of the bottomportion of the clip. Having end walls and intermediate portionsextending from both sides of the bottom portion allows connectors to beconnected on either side of the clip. The connectors in such an assemblyare arranged side-by-side and bottom-to-bottom. Such a configuration maybe preferred, for example, in quad connector assemblies in which twoside-by-side connectors are located on one side of the bottom portionand two side-by-side connectors are located on the other side of thebottom portion.

In a preferred embodiment, the clip comprises certainpolarization-maintaining features which ensure polarization among theconnectors. For example, in the embodiments shown in FIG. 1 and FIG. 2a, the polarization maintaining feature is a rib 26, 26 a, respectively,along the portion of the clip which interfaces with the deeper portion27 of the recess 25 a of the connector (shown in FIG. 2 a). This ribensures that clip can only be secured to the connectors in a particularorientation. In other words, one cannot orient the clips shown in FIGS.1 and 2 by 180° and expect to the rib to be received in the deeperportion of the recesses of the connectors as shown. If the clip isprovided with polarization-maintaining features as described above, itis preferable for the clip to comprise indicia indicating thispolarization. For example, in the embodiments shown in FIGS. 1 and 2 a,the clips 11, 11 a has the indicia “A” on one side and “B” on the other,in accordance with industry practice.

The clip may comprise any resilient material to enable it to beresiliently deflected to separate the intermediate portion and an endwall sufficiently such that they can be slipped over the connector, andthen be released to its initial position, thereby snugly gripping theconnectors. Suitable materials include, for example, plastics andmetals. In a preferred embodiment, the clip comprises a plastic moldedin accordance with the embodiment shown in FIG. 11. A plastic clipallows the intermediate portion and the polarization maintainingfeatures to be integrally molded with the bottom portion and the sidesas shown. Additionally, applicants have found that the use of a plasticclip minimizes EMI issues with respect to the connector assembly. It issuspected that a metal clip, if not properly grounded, may, undercertain circumstances, act as an antenna and become a source ofelectromagnetic interference (EM). Although plastic may be preferred,the reason stated above, a metal clip 11 a may be preferred neverthelessfrom the standpoint of manufacturability as shown in FIG. 2 a. That is,techniques for stamping and forming metal strips are well known in theart, and a single metal strip can be readily formed to have the endwalls and intermediate portions as discussed above. Furthermore, themetal clip 11 a may offer advantages over a plastic clip in that a metalclip may be much thinner than a plastic clip of similar strength.

It should be understood that the foregoing is illustrative and notlimiting and that obvious modifications may be made by those skilled inthe art without departing from the spirit of the invention. Accordingly,the specification is intended to cover such alternatives, modifications,and equivalence as may be included within the spirit and scope of theinvention as defined in the following claims.

1. An optical connector assembly comprising: a plurality of identicalsimplex connectors, each connector comprising at least a housing havinga top, a bottom and two sides, and having a plug end for insertion intoa mating receptacle and a cable end for receiving an optical cable, saidhousing having a recess along each of the two sides; and a clip holdingsaid plurality of connectors together in a side-by-side relationship,said clip having a bottom portion, first and second end walls extendingupward from said bottom portion, and one or more intermediate portionsextending upward from said bottom portion between said first and secondend walls, each of said one or more intermediate portions having a firstend face facing said first end wall and a second face facing second endwall; wherein said first end wall and a first face of one of said one ormore intermediate portions are received in the recess of one of saidconnectors and said second end wall and a second face of one of said oneor more intermediate walls are received in the recess of another of saidconnectors such that said connectors are held in a side-by-sidearrangement; wherein said recess of each connector is deep enough toreceive said clip such that said clip does not extend beyond theperiphery of said housing; and wherein said recess has a deep portionand said clip has a rib asymmetrically located thereon such that andsaid rib is received in said deep portion to hold said connectors in aside-by-side arrangement in a certain orientation.
 2. The connectorassembly of claim 1, wherein each connector has a latch connected tosaid housing.
 3. The connector assembly of claim 2, wherein said recessis below said latch.
 4. The connector assembly of claim 3, wherein saidrecess extends from one side of the connector down around the bottom ofthe connector and up the other side.
 5. The connector assembly of claim2, wherein said cable end comprises a crimp lug adapted for securing acable to said connector.
 6. The connector assembly of claim 5, whereinsaid recess is in front of said crimp lug.
 7. The connector assembly ofclaim 1, wherein a plurality of connector is two connectors.
 8. Theconnector assembly of claim 1, wherein said connectors are small formfactor connectors.
 9. The connector assembly of claim 1, wherein saidclip comprises a resilient material enabling it to be snapped onto eachconnector.
 10. The connector assembly of claim 9, wherein said clipcomprises metal.
 11. The connector assembly of claim 10, wherein saidclip is a single piece of metal bent to form each said end walls andsaid intermediate portions.
 12. The connector assembly of claim 9,wherein said clip comprises plastic.
 13. The connector assembly of claim1, wherein said clip comprises one intermediate portion.
 14. Theconnector assembly of claim 1, wherein said each connector is connectedto an optical cable.
 15. The connector assembly of claim 14, whereinsaid optical cable is jacketed.
 16. The optical connector assembly ofclaim 1, wherein said clip is marked to indicate the orientation of saidrib.
 17. The optical connector assembly of claim 16, wherein said firstside wall is marked with an “A ” and said second side wall is markedwith a “B.”
 18. The optical connector assembly of claim 1, wherein saidfirst and second walls and said one or more intermediate portions arethicker at the bottom than at the top, and said recess is deeper at thebottom to receive said first and second side walls and said intermediateportions such that said clip does not extend beyond the periphery ofsaid housing.
 19. The optical connector assembly of claim 18, whereinfirst and second side walls have an outer face and an inner face, saidouter face extending perpendicularly from said bottom portion and saidinner face extending at an angle such that said first and second sidewalls are thicker at the bottom than at the top.
 20. The opticalconnector assembly of claim 1, wherein said connector is an LC-typeconnector.
 21. The optical connector assembly of claim 1, wherein saidconnector comprises a generally rectangular housing and said first andsecond end walls and intermediate portions extend substantiallyperpendicularly from said bottom portion.
 22. The optical connectorassembly of claim 1, wherein said connector also comprises an individualactuation pad for acquitting said latch.
 23. The optical connectorassembly of claim 22, wherein said actuation pad is integral to a latchsnag guard which is attached to the connector housing.